1. Field of the Invention
The invention relates to a pressure sensor which translates a hydraulic pressure into an electrical signal, and more particularly, to a pressure sensor of the type including a movable body which is subjected to a hydraulic pressure causing a displacement which is converted into an electrical signal.
2. Discussion of the Prior Art
A conventional arrangement is known in which a diaphragm is subject to hydraulic pressure and is normally urged by a coiled spring to oppose the hydraulic pressure, with the diaphragm being connected to a slider on a potentiometer. In this arrangement, the potentiometer provides an analog voltage corresponding to the amount of movement of the diaphragm when the latter is subjected to hydraulic pressure. With this pressure sensor, it is desirable that a thin film resistor forming the potentiometer exhibits a high abrasion resistance and provides a stable output voltage for a given slider position. It is also desired that the movable body and the slider be mechanically connected together with a minimal degree of rattling and that a stabilized contact is maintained between the slider and the thin film resistor in the presence of oscillations or shocks. However, because the slider is brought into contact with the thin film resistor under pressure, an abrasion or oscillations may cause an unstabilized output voltage to be produced in respect to the measured hydraulic pressure.